The present invention relates in general to railroad wayside signal systems. More specifically, the present invention pertains to the maintenance of such systems and the alignment of signal lights incorporated in such systems.
Wayside signal systems are used to control the speed and position of a locomotive on a railroad track relative to other locomotives on the track. These systems typically consist of a mast that is mounted to a support structure that is positioned adjacent to a railroad track. A signal head is mounted to the mast, and one or more signal lights are mounted on the signal head so a locomotive operative in an approaching locomotive can see the signal lights.
Some of the support structures of the signal systems may take the form of a bridge or cantilevered arm extending over the railroad track. These support structures include ladders and catwalks so signal maintainers may reach the signaling systems for maintaining and manually aligning the signal head and signal lights. The signaling systems are mounted on such a structure above the track with the signal lights in view of locomotive operators. Alternatively, the signal head may be mounted directly to the support structure above the railroad track and may not require a mast.
Other signaling systems include a support structure, such as a large concrete block or steel frame buried in the ground beside the railroad track. A base of the mast is mounted to the support structure and extends vertically in an upright position. The signal head is mounted on the mast at about twelve feet to nineteen feet above the ground so a locomotive operator can see the signal lights. In addition, such systems may also be equipped with a platform and ladder so that a signal maintainer can reach the signal lights and signal head for purposes of manually aligning the signal lights and/or providing maintenance to the signal head and signal lights.
In either case, the signal system utilizes a mounting system that enables the signal head to rotate or pivot on two axes, in order to obtain a proper alignment of the signal lights with respect to an approaching locomotive. These mounting systems include one or more bolts and nuts on the bolts, which are manually rotated on the bolt to tilt the signal head on one or both of the axes. Two signal maintainers are necessary to achieve the proper alignment of the signal lights with respect to an on-coming locomotive. A first signal maintainer is positioned on the ground adjacent to the railroad track a predetermined distance from the mast. A second signal operator is positioned on a platform, catwalk or ladder on the support structure. The second signal maintainer manually adjusts the position of the signal head and signal lights according to instructions from the first signal maintainer on the ground.
These present signaling systems expose the signal maintainers to injury because the signal maintainers must climb up to nineteen feet above the ground, and in some instances over the railroad track to align or maintain the signal lights. In addition, ladders and platforms installed on such systems increase the cost of production and installation of the signaling systems.